Manufacture of soap



Feb. 13, 1945. A. T. SCOTT 2,369,257

' MANUFACTURE 0F SOAP Filed Feb. {26 1942 2 Sheets-Sheet l Parfly Spent Lye I we Part1 1 My r We StrongLye 5 Neutral Put- Mixer 511R. 9/ Sohlhon 17 Lye, Watr u F'Y G Mixer J Soap *PlCr-L INVE NTOR AshtonT. Scott ATTORNEY Feb. 13, 1945. T, scoTT MANUFACTURE OF SOAP 2 Sheets-Shet 2 Filed Feb. 26, 1942 R .m mm C m8 T n .m In S A BY M l I ATTORNEY prior application, the soap and aqueous phases fats form harder grains than. others.

unusual hardness.

Patented Feb. 13, 1945 MANUFACTURE SOAP Ashton T. Scott, Bryn Mawr, Pa., assignor to The Sharples Corporation, Philadelphia, Pa., a corporation of Delaware Application February 26, 1942, SerialNo.j432,3 75

10 Claims. (omen-418') H The present invention relates the art of soapmaking, and this application is a continuation in part of my co-pending-application, Serial No. 333,547, filed May 6, 1940, now Patent 2,300,749, November 3, 1942. My prior application pertains to a continuous process for manufacture of soap by continuously mixing a saponifying reagent with a source of fat to effect saponification thereof, and separating soap formed by the saponification reaction from spent saponifying reagent by centrifugation. The present application pertains to-the special procedure described on pages -12 and 13 of that prior application, by which the soap formed in the continuous soap-making operation is discharged from the centrifugal rotor and passed to the zone of subsequent treatment or use under the influence of its own rotational inertia.

As pointed out in my prior application referred to above,the problem of removal of the soap from the centrifugal inwhich it. is separated from the aqueous phase presents'very considerable difficulty in connection with the continuous manufacture of soap, withthe aid of centrifugal separators. This. problem becomes greater as the thoroughness of the graining operation by which the soap is precipitated and washed from the spent lye is improved. In accordance with the principal embodiment of the invention of my are discharged from the-respective .centrifugals under liquid balance over weirs, and the soapis discharged from the centrifugalcovers into which it is discharged over the'weirs with the aidof an aqueous liquid which i's separately introduced into the covers. By'the present invention the soap may be discharged from the centrifugal even in cases in which it is too hard' and granular to be discharged over a weir.

It is a Well-known fact in the art of soap manufacture that soaps formed from certain These harder-grained soaps are difficult, and some times impossible, to discharge over alweir of a centrifugal separator; and'a feature of the in'-- vention'c'onsistslin the'fact' that it renders the process of continuous centrifugal soap-making feasible, even with fats, which form grains of In accordance. with the'p'resent invention, instead of. dlsch'arging the soap. into a centrifugal cover across a weir, it is discharged from the centrifugal; and may be passed from the centrifugal into a conduit leading to the following FEW??? .9WF m f n i ia TQ .W- ze n ut st s. e a le ofswhetherfthei I In the practice of the invention as illustrated .in Figure 1 of the drawings, a saponifiable mass,

.source of fat in-this mixer,

'complish this endin accordance with the; present invention, a stationary skimming nozzle or sim lar dislodging tool is positioned within the centrifugal rotorat a 'pointsubstantially tangential to the path ofgrotation of the soap in that rotor under the influence of centrifugal force, with the result that the kinetic energy-of the soap caused by its movement around the axis of the centrifugalrOtor is largely converted into pressure within a pipe connected' to'the skimming nozzle,

and the soap is accordingly-removed from the centrifugal rotor under the influence of its own Figure 2 is acentrallongitudinalcross section through a centrifugal separator usedin the practice of the "invention, and p Figure 3 is a cross section on the line .3-'-.3 of

Figure 2. v

such as neutral fat from container I0, is passed by pump H to a mixer 12, where it is mixed with a saponifying reagent. passed. from con- .tainerM by pump I5 .into confluence with'the The mixer l 4 may be any suitable type of mixer .adapted to efi ect yiolent'mixing.,ofthe saponi- 35 .fying reagent with the source of fat, but a multistage high-speed'mechanical mixer is preferred .for performanceof the mixing function. The

mixin of the saponifying reagent with the fat "at a saponifying temperature results in formation lfor subsequent centrifugal separation from aqueous phase; -While thesalt solution is indicated on the flow sheet as being added at an advanced stage. of the mixer, it may be. added at anysuitable point, and there are certainIVeryTdefinite advantages inadding v.it a't-an earlier stage, either. separately, orwas a part of the solutionlof fsa-"ponifying reagent, as taught in., my1.co-pending application SerialNo. 334,297,. filed May 10, .1940,

. f'onManufacture of soap, now Patent-2,300,750, November. 3, 1942. In connection with these fea- .tu res of the invention, it includes saponifying salting-out step is performed subsequent to complete formation of soap in the mixer, at an intermediate stage of soap formation, or at the time the soap is formed by introduction of the saltbe added to effect saponification of a substantialproportion of the fat, and that the soap result-.

from solution by the presence. of a suitable agent for effecting that end; this grainingor precipitating agent may, for example, be" a suitable electrolyte. As an example of the possibilities of graining within the broad scope of .theinvention, it may be pointed out that the graini-ng operation may be accomplished by addition to the reaction mixture of an amount of the sap'onifying reagent in excess of that required to react with the fatunder treatment in manufacture of soap.

The violent agitation of the soap-containing mass is preferably continued during the progress of this material practically up to-the i'nstant when this material enters the centrifugal separator l8. By continuing the agitation in this manner, the mass is maintained in a condition of substantially uniform dispersion of the grained soap within the aqueous hase, with the result that continuous and fairly uniform feed to the centrifugal separator l8 occurs. The centrifugal separator [8 may 'be of any type suitable for discharge of the soap substantially tangentially from the centrlfugal under its own rotational inertia while separating. and separately discharging the aqueous phase, I prefer to use a centrifugal of the type illustrated in the patent to Jones 2,089,123, and in Figures 2 and 3 of the present drawings.

Referring to Figure 2 of the drawings, the numeral 30 designates a centrifugal rotor, The mixture of the grained soap with aqueous phase leaving the mixer 12 is fed to the centrifugal ing' with a central tube 32' constituting a part of the centrifugal rotor. The mixture tobe centrifuged passes from the central tube 32 into the main body of the rotor through radially extendi'ng passages 33'. The rotor contains a plurality of stratifying plates 34 adaptedto facilitate centrifugal separation of constituents of the mixture minimizes cloggage of the stratifying" plates by the soap;

l The rotor is provided with a frustc-conical dividing wall 35, and the heavier material sedimented as the outer stratum within the rotor is continuously discharged around the outer edge of this dividingwall and through passages'36 located between this dividing wall and the upper part 311 of the rotor. This aqueous phase is continuously discharged into-the'receiving cover-38 of the centrifu'gal. A dislodging tool in the form of'a skimming nozzle 39 which is 'reciprocabletowardand ing from this reaction be grained or precipitated away from the stratum of soap occupying the inner radial zone of the material stratified within the rotor is provided for discharge of this curdy material.

A consideration of the mode of operation of this machine in the separation of soap from aqueous phase after discharge from the mixer l2 will illustrate the nature of the present invention. In the separation of soap from the aqueous phase,

the rotor is first set in rotation, and the mixture from the mixer I2 is fed to the main body of the rotor through the feed nozzle 3| and the central spent lye solution will be sedimented from the soap and flow outwardly, around the frusto-conirotor by means of a feed nozzle 3| communicatcal dividing wall 35 and through the passages 36 into the liquid receiving cover 38. The layer of soap, accumulating within the portion of the rotor lying inwardly of the inner termini of the discs 34-, will be discharged through the skimming nozzle 39.

The rotor 3i) preferably includes means 40 for maintaining the soap which occupies the portion of the rotor lying inwardly of the-inner termini of the stratifying plates 34 at a speed of rotation substantially the same as the speed of the rotor. These means constitute, in the form of the invention illustrated, ac'ccelerator structure in the form of a plurality of radially extending webs or wings which may be formed integrally with the central tube 32 andextendradially from this central tube to the inner termini of the stratifying plates 34., These wings contain portions in the form of webs 4i extending a substantial distance longitudinally of the rotor and occupying the full depth of the inner soap-stratum within the rotor. These webs, at their outer radial extremities, are preferably enlarged to form ribs 42, which-also assist in maintaining the viscous soap at approximately the speed of bowl rotation, and which extend throughout substantially the entire longitudinal zone of the rotor occupied by the viscous soap. The zone of the rotor adjacent theskimming nozzle 39 is of course left freeof accelerator structure in order to afford provision for unobstructed movement of the skimming nozzle. The upper ends of the ribs 42 are preferably connected together by means of an annular frusto-conical rigidifying disc 43. The outer radial extremities of the ribs preferably abut the inner radial extremities of the stratifying plates 34 and tend to center these stratifying plates within the rotor. One of these ribs is preferably provided with' a key 44, as illustrated,v

which enters into slots formed in the stratifying plates and thus insures the rotation of these plates at the same speed as the rotor.

- (ill As pointed out above, the soap accumulating as the inner stratum in the centrifugal rotor is ,continuously impelled, under energy derived from its own inertia of rotation, in a substantially'tan gential direction into" the skimming nozzle} 39 and the piping connectedwith that skimming aqueous phase" in this. second centrifugal is discharged'to the next zone of treatment or use with the aid of a skimming nozzle in the same manner as that employed in discharge of soap from the centrifugal I8, and aqueous phase separated similarly'to the aqueous phase from centrifugal I8 may be returned by pump 24 to :container' I3, from which it is passed into confluence-with further saponifiable materialin the mixer, I2 to assist in the primarysaponification step. Soap discharged from centrifugal 22 may be mixed with water to effect the fitting operation, and'the resulting mixture then "subjected 'tovcentrifugation to separate nigre' fromneat soap in a centrifugalsimilar to centrifugals I8 and 22, the neat soap being discharged'bya skimming nozzle, while the aqueous phase '(nigre) is separately discharged; I 1 a While an embodiment of the-inventionz:has been illustrated in which soap discharged from the centrifugal I8 is passed from that centrifugal to the mixer l9 under impelling force derived from rotation in the 'centrifugal I8, it will be evident that a pump ma be providedin thconduit connecting the centrifugal I8 with the. mixer I9, 'if desired. In either case, an important advantage is attainedin practice of the present in'- vention'by deriving the necessary force for dis charging sedimented soap'from the zone of centrifugation, 'from the soap itself, as'that soap rotates in the centrifugal in which it is stratified.

A furtheradvantage of the invention'consists in the fact that it can be eilectively used in connection with an operation including spraying the soap withan aqueous solution of an electrolyte, such as brine, during the centrifugal sep-' aration of the soap from aqueous phase. Thus, brine may be fed from container I6 through conduit 45 and sprayed through openings of tube 46 from this conduit onto the rotating body of soap in the centrifugal. way, and using strong brine or other strong electrolyte solution as the washing and graining agent sprayed, through the openings'of the tube 46, it is possible to produce a very granular soap stratum, with the result that unusually efficient washing is obtained. In spite of the fact that the soap stratum is made quite granular by this operation, it is possible to discharge it under the effect of its own inertia throughthe skimming nozzle 39. Thus, by providing a process which renders discharge of a more granular soap from the centrifugal possible, thorough washing of the soap in the centrifugal is rendered feasible, with the result that the soap discharged from the centrifugal of the first stage is a much uct than could otherwise be obtained.

Various modifications are possible within the scope of the invention, and I do not therefore wish to be limited except by the scope of the following claims.

I claim:

1. In the separation of grained soap from saagent solution from said rotor, and separately discharging sedimented soap from said rotor'substantially tangentially under the influence of it own rotational inertia by projection. of said soap against a non-rotating dislodging tool main- By operating in this purer prodtained -in:the.path of {rotation of said sedimented soap Within said rotor;

z 2; :In the manufacture of soap,,the continuous process comprising saponifying and graining a saponifiable material to form a mixture of soapprocess comprising saponifying and graining a saponifiable material toform a mixture of soap and aqueous phases, passingthe mixture of soap andaqueous phases into the rotor of a centrifugal separator, causing sedimentation of aqueous phase from the soap by rotation ,of the rotor, discharging aqueous phase from said rotor," and separately discharging sedimentedsoap from said rotor by maintaining a non-rotating dislodging tool-in the path of the rotating body of sedimented soap in said centrifugal rotor andthereby propelling said soap'from said rotor.

4; In th manufactureof soap, the continuous process comprising saponifying and graining a saponifiable material to form a mixture of soap and ,aqueou phases, passing the mixtureof. soap and aqueous phases into the. rotor of a centrifugal separator, causing, ,sedimentationhof aqueous phaseifrom the soap by rotation of the rotor, dis,- charging aqueous phase from said rotor, and separately discharging sedimented soap from said rotor bymaintaining a non-rotating skimming nozzle in the path of the rotating body of.sedimented soap in said centrifugal rotor and thereby propelling said soap from said rotor. Y

5. In the manufacture of soap, the continuous process comprising saponifying and 'graining a saponifiable material to form a mixture of soap and aqueous phases, passing the mixture of soap and aqueous phases into the rotor of a centrifugal separator, causing sedimentation of aqueous phase from the soap by rotation of the rotor, discharging aqueous phase from said rotor, and separately discharging sedimented soap from said rotor and removing said separated sedimented soap from the centrifugal separator by maintaining a non-rotating skimming nozzle in the path of the rotating body of.stratified soap in said centrifugal rotor and thereby propelling said soap through said skimming nozzle into a conduit by which it is removed from said centrifugal separator under force derived from its inertia of rotation in said rotor.

6. In th manufacture of soap,' the continuous aqueous phase from the soap byrotation of the rotor, discharging aqueous phase from said rotor, separately discharging sedimented soap from said rotor and removing said separated sedimented soap from the centrifugal separator by maintaining a non-rotatingskimming nozzle in the path of the rotating body of sedimented soap in said centrifugal rotor and thereby propelling said soap through said skimming nozzle intoa dnduit -by which it is-"rexnoved' from said cen' trifugal' separator under force derived from its assume-z inertia of rotation in' said rotor, and delivering said soap from said conduit into amixer in which it is mixed with a further quantity'of saponifying reagent in a further stage of the process. 7. In I the manufacture of soap, the process comprising separating soap from aqueous phase by passing a mixture of soap and aqueous phase into the rotor of a centrifugal separator, causing sedimentation of aqueous phase from the soap by rotation of the rotor, washing the sedimented soap by introducing an electrolyte solu-- tion into the central portion of said rotor within the soap stratum formed by sedimentation of said soap, discharging aqueous phase from .said

rotor, and separately discharging sedimented soap from sa d rotor under the influence of its own rotational inertia by projection of said-soap against a non-rotating dislodging tool maintained irl'the pathof rotation of said'sedimented soap within said rotor.

(8'. In the manufacture of soap, the continuous process comprising 's'ap'onifying a saponifiable material therewith graining the sapon'ified' mass to form a mixture of soap and aqueous phases,

passing the mixture of soap and aqueous phases into the rotor of a centrifugal separator, causing sedimentation of aqueous phase from the soap by rotation of the rotor, discharging aqueous phase from said rotor, and separately discharging seditinented soap tangentially from said rotor under the influence of its own rotational inertia by projection of said-soap against a non-rotating dislodging tool maintained in the path of rota.- :1 7 tion of said sedimented soap'within said rotor.

-19, In the: manufactureot: soap; the continuous process comprising saponifying and grainingxa saponifiable material by substantially simultane ous addition thereto Of-a s'aponifying reagent: and a. salt to form a. mixture. or soap and aqueous phases, passing the mixture of soap and aqueous phases. into the rotor of a centrifugal separator, causing sedimentation of aqueousphasefrom the soap by. rotation of, the rotor, discharging aqueous phase ,from said rotor, and separately dis,-

charging sedimented soap substantially tangene tially from said rotor under the influence of its ownrotational inertia by projection of said soap against a non-rotating dislodging tool 'maintained in the path of rotation of said sedimented soap within; said rotor.

-';i.'10.;In-the manufacture of soap, the continu ous process comprising saponifying'and graining a saponifiable. material by" addition thereto of asufficient' molecular excess of aisaponiiying re= agent to perform th;v saponifying" and grainine 1 ASHTON-'1'. "sco'r'r.

CERTI FICATE OF CORRECTION Patent 'No. 2,569,257. February 15, 19L 5.

ASHTON T. SCOTT.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows Page i first column, line 25, claim 8, for "therewith" read --thereafter--; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 26th day of June, A. D. 1915.

Leslie Frazer (Seal) Acting Commissioner of Patents. 

